Easy Access Articles of Footwear

ABSTRACT

Footwear includes a fluid-filled bladder system having: (a) a foot-support bladder system, (b) a foot-securing bladder system, and (c) a fluid-flow control system for controlling fluid flow between these bladder systems. The fluid-filled bladder system may be changed between: (i) a foot-insertion configuration in which the foot-support bladder system contains a first volume of fluid (e.g., V 1 ) and the foot-securing bladder system contains a second volume of fluid (e.g., V 2 ), and (ii) a foot-securing configuration in which the foot-support bladder system contains a third volume of fluid (e.g., V 3 ) and the foot-securing bladder system contains a fourth volume of fluid (e.g., V 4 ), wherein V 1 &gt;V 3  and V 2 &lt;V 4 . Additionally or alternatively, articles of footwear may include a friction reducing agent located at or near the foot-receiving opening to allow easier foot access, e.g., in a hands-free manner and/or without collapsing the upper.

RELATED APPLICATION DATA

This application is a non-provisional of and claims priority benefits based on U.S. Provisional Patent Application No. 62/413,193 filed Oct. 26, 2016 entitled “Easy Access Articles of Footwear.” U.S. Provisional Patent Application No. 62/413,193 is entirely incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to the field of footwear. Some aspects of the present invention pertain to articles of footwear that are easy to put on, easy to secure, and/or have “hands-free,” “laceless,” “buckleless,” and/or “strapless” securing characteristics.

BACKGROUND

Conventional articles of athletic footwear include two primary elements, namely, an upper and a sole structure. The upper provides a covering for the foot that securely receives and positions the foot with respect to the sole structure. In addition, the upper may have a configuration that protects the foot and provides ventilation, thereby cooling the foot and removing perspiration. The sole structure is secured to a lower surface of the upper and generally is positioned between the foot and any contact surface. In addition to attenuating ground reaction forces and absorbing energy, the sole structure supports and protects the foot and may provide traction and help control potentially harmful foot motion, such as over pronation. General features and configurations of the upper and sole structure are discussed in greater detail below.

The upper forms a void on the interior of the footwear for receiving the foot. The void has the general shape of the foot, and access to the void is provided at an ankle opening. Accordingly, the upper may extend over the instep and toe areas of the foot, along the medial and lateral sides of the foot, and around the heel area of the foot. A lacing system often is incorporated into the upper to allow selective changes to the size of the ankle opening and to permit the wearer to modify certain dimensions of the upper, particularly girth, to accommodate feet with varying proportions. In addition, the upper may include a tongue that extends under the lacing system to enhance the comfort of the footwear (e.g., to moderate pressure applied to the foot by the laces). The upper also may include a heel counter to limit or control movement of the heel.

The sole structure generally incorporates multiple layers that are conventionally referred to as an “insole,” a “midsole,” and an “outsole.” The insole (which also may constitute a sock liner) is a thin member located within the upper and adjacent the plantar (lower) surface of the foot to enhance footwear comfort, e.g., to wick away moisture and provide a soft, comfortable feel. The midsole, which is traditionally attached to the upper along the entire length of the upper, forms the middle layer of the sole structure and serves a variety of purposes that include controlling foot motions and attenuating impact forces. The outsole forms the ground-contacting element of footwear and is usually fashioned from a durable, wear-resistant material that includes texturing or other features to improve traction.

TERMINOLOGY/GENERAL INFORMATION

First, some general terminology and information is provided that will assist in understanding various portions of this specification and the invention(s) as described herein. As noted above, the present invention relates to the field of footwear. “Footwear” means any type of wearing apparel for the feet, and this term includes, but is not limited to: all types of shoes, boots, sneakers, sandals, thongs, flip-flops, mules, scuffs, slippers, sport-specific shoes (such as track shoes, golf shoes, tennis shoes, baseball cleats, soccer or football cleats, ski boots, basketball shoes, cross training shoes, etc.), and the like.

The terms “forward” or “forward direction” as used herein, unless otherwise noted or clear from the context, mean at, toward, or in a direction toward a forward-most toe area of the footwear structure or component. The terms “rear,” “rearward,” or “rearward direction” as used herein, unless otherwise noted or clear from the context, mean at, toward, or in a direction toward a rear-most heel area of the footwear structure or component. The terms “lateral” or “lateral side” as used herein, unless otherwise noted or clear from the context, mean the outside or “little toe” side of the footwear structure or component. The terms “medial” or “medial side” as used herein, unless otherwise noted or clear from the context, mean the inside or “big toe” side of the footwear structure or component.

In the following description of various example structures in accordance with the invention, reference is made to the accompanying drawings, which form a part hereof, and in which are shown by way of illustration various example foot support structures, components thereof, and articles of footwear in accordance with aspects and examples of the invention. It is to be understood that other specific arrangements of parts and structures may be utilized, and structural and functional modifications may be made without departing from the scope of the present invention. Also, while the terms “top,” “bottom,” “front,” “back,” “rear,” “side,” “underside,” “overhead,” “over,” “under” and the like may be used in this specification to describe various example features and elements of the invention, these terms are used herein as a matter of convenience, e.g., based on the example orientations shown in the figures and/or the orientations in typical use (e.g., orientation when incorporated into an article of footwear supported on the bottom of its sole structure on a horizontal support surface).

SUMMARY

This Summary is provided to introduce some concepts relating to this invention in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the invention.

While potentially useful for any desired types or styles of footwear, aspects of this invention may be of particular interest for casual wear shoes, athletic shoes, etc.

Some aspects of this invention relate to articles of footwear that include an upper having an exterior surface and a sole structure engaged with the upper, wherein at least one of the sole structure and the upper define an interior volume configured to receive a wearer's foot. These articles of footwear further include a fluid-filled bladder system that has: (a) a foot-support bladder system providing at least a portion of a plantar support surface (for directly or indirectly supporting a plantar surface of a wearer's foot), wherein the foot-support bladder system is engaged with or formed as part of at least one of the upper or the sole structure, (b) a foot-securing bladder system engaged with the upper and located at least partially within the exterior surface of the upper, (c) a fluid-flow connecting system placing the foot-support bladder system and the foot-securing bladder system in fluid communication with one another, and (d) a fluid-flow control system for controlling flow of fluid between the foot-support bladder system and the foot-securing bladder system through the fluid-flow connecting system. In at least some aspects of this invention, the fluid-flow control system may be configured (e.g., switchable) to change the fluid-filled bladder system between: (i) a foot-insertion configuration in which the foot-support bladder system contains a first volume of fluid (e.g., V₁) and the foot-securing bladder system contains a second volume of fluid (e.g., V₂), and (ii) a foot-securing configuration in which the foot-support bladder system contains a third volume of fluid (e.g., V₃) and the foot-securing bladder system contains a fourth volume of fluid (e.g., V₄), wherein the first volume of fluid is greater than the third volume of fluid (i.e., V₁>V₃) and the second volume of fluid is less than the fourth volume of fluid (i.e., V₂<V₄). Additionally or alternatively, in such structures, a first portion of an outer surface of the foot-securing bladder system may extend further away from the exterior surface of the upper and/or further away from the opposite surface of the bladder in the foot-securing configuration as compared to a position of this first portion of the outer surface of the foot-securing bladder system in the foot-insertion configuration. The foot-securing bladder system may include one or more foot-securing chambers. In the foot-securing configuration, one or more portions of the outer surface of the fluid-filled bladder system may engage, “squeeze,” contact, and/or come in close proximity to a wearer's foot in order to help maintain the article of footwear on the wearer's foot.

The “foot-insertion configuration” described above may be the same as or similar to a “foot-removal configuration,” i.e., a configuration of the fluid-filled bladder system when a user removes his/her foot from the shoe. Both of these terms are used in the discussion below, but may refer to generally the same configuration of the component parts.

Additional aspects of this invention relate to methods of securing articles of footwear, e.g., to a wearer's foot. Such methods may be used, for example, in securing articles of footwear of the types described above to a wearer's foot. These methods may include providing an article of footwear including: (a) an upper having an exterior surface, (b) a sole structure engaged with the upper, wherein at least one of the sole structure and the upper define an interior volume configured to receive a wearer's foot, and (c) a fluid-filled bladder system having: (i) a foot-support bladder system providing at least a portion of a plantar support surface for a wearer's foot, wherein the foot-support bladder system is engaged with or formed as part of at least one of the upper or the sole structure, (ii) a foot-securing bladder system engaged with the upper and located at least partially within the exterior surface of the upper, and (iii) a fluid-flow connecting system placing the foot-support bladder system and the foot-securing bladder system in fluid communication with one another.

To secure this example article of footwear, e.g., to a wearer's foot, by this method, a force is applied to the foot-support bladder system (e.g., by insertion of a wearer's foot into the footwear interior volume), and in response to this applied force, fluid is moved from the foot-support bladder system to the foot-securing bladder system through the fluid-flow connecting system. This may be accomplished, for example, by decreasing the volume of the foot-support bladder system (and/or the volume of fluid in the foot-support bladder system) in response to the applied force (e.g., reducing its volume and/or the volume of fluid in it from V₁ to V₃, as described above), which causes fluid to move into the foot-securing bladder system (e.g., to increase its volume and/or the volume of fluid in it from V₂ to V₄, as described above). In at least some examples, the moving fluid may cause a first portion of an outer surface of the foot-securing bladder system to extend further away from the exterior surface of the upper (e.g., extend in a direction further inward into the interior volume of the article of footwear) as compared to a location of the first portion of the outer surface of the foot-securing bladder system before the applying force step. The fluid-flow connecting system may be closed off with the force still applied to the foot-support bladder system (e.g., by a switch or valve) in order to maintain the foot-support bladder system at its decreased volume condition and in order to maintain the foot-securing bladder system at its increased volume condition. The increased volume of the foot-securing bladder system in this configuration may move one or more portions of the outer surface of the foot-securing bladder system to engage, “squeeze,” contact, and/or come in close proximity to a wearer's foot in order to help maintain the article of footwear on the wearer's foot.

Additional or alternative aspects of this invention relate to methods of loosening articles of footwear, e.g., from a wearer's foot. Such methods may be used, for example, in loosening articles of footwear of the types described above from a wearer's foot and/or loosening articles of footwear secured in the manners described above. These methods may include providing an article of footwear having: (a) an upper including an exterior surface, (b) a sole structure engaged with the upper, wherein at least one of the sole structure and the upper define an interior volume configured to receive a wearer's foot, and (c) a fluid-filled bladder system having: (i) a foot-support bladder system providing at least a portion of a plantar support surface for a wearer's foot, wherein the foot-support bladder system is engaged with or formed as part of at least one of the upper or the sole structure, (ii) a foot-securing bladder system engaged with the upper and located at least partially within the exterior surface of the upper, and (iii) a fluid-flow connecting system placing the foot-support bladder system and the foot-securing bladder system in fluid communication with one another.

To loosen this example article of footwear, e.g., from a wearer's foot, by this method, a force applied to the foot-support bladder system is reduced (and optionally fully removed), e.g., reduced as compared to when a user stands on the sole, lands a step or jump, etc. (e.g., by the wearer sitting down or lifting the foot so there is no contact with the ground or other support surface). When the reduced force is present, fluid is moved from the foot-securing bladder system to the foot-support bladder system through the fluid-flow connecting system. This may be accomplished, for example, by decreasing the volume of the foot-securing bladder system and/or the volume of fluid in the foot-securing bladder system (e.g., reducing its volume and/or the volume of fluid in it from V₄ to V₂, as described above), which causes fluid to move into the foot-support bladder system (e.g., to increase its volume and/or the volume of fluid in it from V₃ to V₁, as described above). In at least some examples, the moving fluid may cause a first portion of an outer surface of the foot-securing bladder system to move toward the exterior surface of the upper (e.g., contract and/or extend in a direction further outward and away from the interior volume of the article of footwear) as compared to a location of the first portion of the outer surface of the foot-securing bladder system before the force was reduced. The fluid moving step may be initiated, for example, by opening the fluid-flow connecting system (e.g., opening a switch or valve), which may: (a) allow the foot-securing bladder system to reduce in hardness and/or pressure and/or to move away from the wearer's foot as the foot is removed (and allow the foot-securing bladder system to decrease its volume and/or the volume of fluid therein) and (b) allow the foot-support bladder system to increase its volume and/or the volume of fluid therein as the foot is removed. The fluid-flow connecting system of this example may be opened and/or otherwise activated (to allow the fluid flow) before or after the force is reduced. The decreased volume of the foot-securing bladder system in this foot-removal configuration may move one or more portions of the outer surface of the foot-securing bladder system somewhat away from the wearer's foot in order to provide a “looseness” to facilitate footwear removal.

If desired, in accordance with at least some examples of this invention, the fluid-filled bladder system (including, consisting essentially of, or consisting of the foot-support bladder system, the foot-securing bladder system, and the fluid-flow connecting system) may be formed as a “closed” system, meaning that the bladders and their interconnections are fluid-tight and no external air or other fluid can be introduced into the fluid-filled bladder system and none leaves the fluid-filled bladder system (at least is not intentionally discharged). In this manner, in at least some examples of this invention, any fluid moved in the fluid-filled bladder systems, the tightening methods, and/or the loosening methods will involve only movement of fluid between the foot-support bladder system and the foot-securing bladder system through the fluid-flow connecting system.

Articles of footwear in accordance with still other additional or alternative aspects of this invention may include: (a) a sole structure; and (b) an upper engaged with the sole structure, wherein the upper (i) includes an exterior structure (e.g., an exterior surface) extending in a direction away from the sole structure and (ii) at least in part, defines a foot-receiving opening, wherein at least a portion of an upper rim or an upper interior edge of the foot-receiving opening of the upper includes a friction reducing agent, such as a polytetrafluoroethylene containing product. The exterior structure of the upper around the foot-receiving opening may be structured so as to be resistant to buckling under a foot insertion force applied to the foot-receiving opening. This may be accomplished, for example, by providing support ribs as part of the exterior upper structure, by providing a stiff/rigid “exoskeleton” type structure around at least a portion of the foot-receiving opening, by making the heel portion of the upper from a thick, bend resistant material, etc. Advantageously, this feature may allow a wearer to insert his/her foot into the upper in a “hands-free” manner. Articles of footwear in accordance with this aspect of the invention may include any of the fluid-filled bladder systems, “foot-support bladder systems,” and/or “foot-securing bladder systems” described above and/or may be configured to provide any of the “securing methods” and/or “loosening methods” described above.

Additional aspects of this invention relate to methods of making articles of footwear, e.g., of the various types and structures described above (and described in more detail below) and/or that perform the various functions described above (and described in more detail below).

Given this general description and background information, more specific examples of sole structures, sole structure components, upper structures, upper structure components, and articles of footwear in accordance with aspects of this invention will be described with reference to FIGS. 1A-11.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing Summary, as well as the following Detailed Description, will be better understood when read in conjunction with the accompanying drawings in which like reference numerals refer to the same or similar elements in all of the various views in which that reference number appears.

FIGS. 1A-1C show various views of an example article of footwear according to some aspects and examples of this invention;

FIGS. 2 and 3 provide alternative examples of fluid-filled bladder systems in accordance with various aspects and examples of this invention;

FIGS. 4A-4D provide various views illustrating examples of differences between example (a) foot-insertion or foot-removal configurations and (b) foot-securing configurations for fluid-filled bladder systems in accordance with various aspects and examples of this invention;

FIGS. 5A-5D provide various views illustrating footwear securing procedures in accordance with various aspects and examples of this invention;

FIGS. 6A-6D provide various views illustrating footwear loosening procedures in accordance with various aspects and examples of this invention;

FIGS. 7A and 7B provide schematic views illustrating various features relating to fluid-flow control systems in accordance with various aspects and examples of this invention;

FIGS. 8A-8E provide various views illustrating example placements of foot-securing bladder systems in accordance with various aspects and examples of this invention;

FIGS. 9A through 10 illustrate various potential features of fluid-filled bladders that may be used in various aspects and examples of this invention; and

FIG. 11 illustrates various example aspects and features of this invention.

The reader should understand that the attached drawings are not necessarily drawn to scale.

DETAILED DESCRIPTION

In the following description of various examples of footwear structures and components according to the present invention, reference is made to the accompanying drawings, which form a part hereof, and in which are shown by way of illustration various example structures and environments in which aspects of the invention may be practiced. It is to be understood that other structures and environments may be utilized and that structural and functional modifications may be made from the specifically described structures and functions without departing from the scope of the present invention.

I. Detailed Description of Specific Examples of this Invention

FIGS. 1A through 1C illustrate various views of one example article of footwear 100 in accordance with various aspects of this invention. While various constructions are possible, this example article of footwear 100 includes an upper 102 (made from one or more parts) having an exterior surface 102E and an interior surface 102I (which may or may not be part of the same individual upper component part or upper member). A sole structure 104 (made from one or more parts) is engaged with the upper 102 (e.g., in conventional manners as are known and used in the art), and at least one of the sole structure 104 and the upper 102 define an interior volume configured to receive a wearer's foot. As further evident from FIGS. 1A-1C, the upper 102 defines a foot-insertion opening 102O (e.g., defined by an upper perimeter rim or edge) that provides access to the interior volume for receiving a wearer's foot. FIGS. 1A-1C further illustrate a sockliner 106 in the interior volume providing a surface that directly contacts a wearer's foot in use (and overlaying a portion of the fluid-filled bladder system, as will be described in more detail below).

The upper 102 and/or the sole structure 104 may have any desired structures, component parts, and the like, without departing from this invention, including structures, component parts, and the like as are conventionally known and used in the footwear arts. Details of such conventional parts will be not described herein.

Footwear 100 in accordance with at least some aspects of this invention will include a fluid-filled bladder system 110, examples of which will be described in more detail below in further conjunction with FIGS. 2-10. The fluid-filled bladder system 110 of these examples provides at least two functions, namely, a foot supporting function (e.g., for supporting at least a portion of a plantar surface of a wearer's foot) and a foot securing function (e.g., to at least partially help secure a wearer's foot in the article of footwear 100). In at least some examples, of this invention, the footwear 100 will be designed to be “laceless,” “buckleless,” and/or “strapless” and/or to allow foot insertion in a “hands-free” manner and/or foot-securing in a “pump-free” manner. The fluid-filled bladders included in these articles of footwear can be made by conventional techniques and/or using conventional constructions, e.g., as are known and used in the footwear arts.

Turning additionally to FIG. 2, one example of a fluid-filled bladder system 110 in accordance with some examples and aspects of this invention now will be described in more detail. As shown, this example fluid-filled bladder system 110 includes a foot-support bladder system 120 (including one or more fluid-filled bladder components or chambers) providing a foot support surface 120S for supporting at least a portion of a plantar surface of the wearer's foot (the foot support surface 120S is concealed by sockliner 106 in the views shown in FIGS. 1A-1C and/or may be located beneath a strobel component or other bottom surface of the upper 102). The foot-support bladder system 120 may be engaged with or formed as part of at least one of the upper 102 and/or the sole structure 104 of the article of footwear 100. As shown in the example of FIG. 2, the foot-support bladder system 120 may be configured to support all or substantially all of the wearer's foot (e.g., extending from a heel area to a forefoot area of the shoe through the midfoot area, and optionally from a forward toe area to a rear heel area).

This example fluid-filled bladder system 110 further includes a foot-securing bladder system 130 (including one or more fluid-filled bladder components or chambers), which may be engaged at least with the upper 102 and located at least partially within the exterior surface 102E of the upper 102. While various configurations are possible (examples of which will be described in more detail below), this illustrated example foot-securing bladder system 130 includes four foot-securing chambers 130A, 130B, 130C, and 130D (formed as fluid-filled bladder chambers or components). Any desired number of foot-securing chambers may be provided in an article of footwear 100 without departing from this invention, such as from 1 to 24, and in some examples from 1 to 18, 1 to 12, or even from 1 to 8. In the illustrated examples of FIGS. 1A-2, two foot-securing chambers 130A/130B are provided, e.g., for the heel area and/or midfoot area of the article of footwear 100, and two additional foot-securing chambers 130C/130D are provided longitudinally displaced forward from the first two foot-securing chambers 130A/130B, e.g., for the midfoot area and/or forefoot area of the article of footwear 100. Additionally, as shown in these figures two foot-securing chambers 130A/130C are provided for one side of the article of footwear 100, e.g., for the medial side, and two additional foot-securing chambers 130B/130D are provided for the other side, e.g., the lateral side.

The foot-support bladder system 120 and the foot-securing bladder system 130 in the example fluid-filled bladder system 110 of FIG. 2 are formed as a closed system and are in fluid communication with one another via a fluid-flow connecting system. In the specific example of FIG. 2, each foot-securing chamber 130A, 130B, 130C, and 130D is in direct fluid communication with a fluid-filled bladder of the foot-support bladder system 120, e.g., via a fluid conduit 140A, 140B, 140C, and 140D, respectively. More or fewer fluid conduits may be provided without departing from this invention (e.g., an individual foot-securing chamber 130A, 130B, 130C, and/or 130D may include one or more fluid conduits engaging it and/or placing it in fluid communication with the foot-support bladder system 120 and/or with another bladder chamber or bladder system).

FIG. 3 illustrates an example fluid-filled bladder system 110 in accordance with another example of this invention having a foot-support bladder system 120 and a foot-securing bladder system 130 with four foot-securing chambers 130A, 130B, 130C, and 130D. In contrast to the example structure of FIG. 2, however, in this illustrated fluid-filled bladder system 110 structure, the foot-support bladder system 120 is longitudinally shorter as compared to that of FIG. 2 (e.g., supporting just a heel and/or midfoot region of a plantar surface of a wearer's foot). Also, the fluid-flow connecting system of FIG. 3 differs from that of FIG. 2. More specifically, while one medial side foot-securing chamber 130A and one lateral side foot-securing chamber 130B are in direct fluid communication with the fluid-filled bladder of the foot-support bladder system 120 (via conduits 140A and 140B), the longitudinally displaced forward foot-securing chambers 130C and 130D are not in direct fluid communication with the fluid-filled bladder of the foot-support bladder system 120. Rather, in this illustrated example, the foot-securing chamber 130A on one side of the article of footwear 100 (e.g., the medial side) is in fluid communication with the other forward foot-securing chamber 130C on that side of the article of footwear 100 by a fluid conduit 140E connecting foot-securing chamber 130A with foot-securing chamber 130C. Similarly, the foot-securing chamber 130B on the other side of the article of footwear 100 (e.g., the lateral side) is in fluid communication with the other forward foot-securing chamber 130D on that side of the article of footwear 100 by a fluid conduit 140F connecting foot-securing chamber 130B with foot-securing chamber 130D. One or more direct chamber-to-chamber conduits 140E and/or 140F may be provided on either or both sides of the fluid-filled bladder system 110 without departing from at least some aspects of this invention.

Additionally or alternatively, if desired, combinations of the fluid-flow connecting systems of FIGS. 2 and 3 may be used in a single fluid-filled bladder system 110. As more specific examples, in addition to the fluid conduits 140A-140D shown in FIG. 2, the fluid-filled bladder system 110 of that example additionally could include one or more of the direct securing chamber-to-securing chamber conduits of the types shown by reference numbers 140E and 140F of FIG. 3. Any desired types and/or combinations of chamber 130A-130D connections to fluid sources may be provided.

Next, operation of examples of the fluid-filled bladder system 110 and the article of footwear 100 will be described in more detail, e.g., with further references to FIGS. 4A through 6D. Articles of footwear 100 in accordance with at least some examples of this invention will include a fluid-flow control system 150 for controlling flow of fluid between the foot-support bladder system 120 and the foot-securing bladder system 130 through the fluid-flow connecting system 140. The fluid-flow control system 150 is configured to change the fluid-filled bladder system 110 between: (a) a foot-insertion/foot-removal configuration in which the foot-support bladder system 120 contains a first volume of fluid (e.g., V₁) and the foot-securing bladder system 130 contains a second volume of fluid (e.g., V₂), and (b) a foot-securing configuration in which the foot-support bladder system 120 contains a third volume of fluid (e.g., V₃) and the foot-securing bladder system 130 contains a fourth volume of fluid (e.g., V₄).

More specifically, FIG. 4A schematically illustrates a rear view showing the foot-support bladder system 120 at least partially housed within, supported by, or formed as part of the sole structure 104 for an article of footwear and the foot-securing bladder system 130 at least partially housed within, supported by, or formed as part of the upper 102 for the article of footwear. The upper 102 of this example includes an exterior surface 102E and an interior surface 102I, and the foot-securing chambers (130A and 130B shown in FIG. 4A) are located between the exterior surface 102E and the interior surface 102I. The exterior surface 102E and the interior surface 102I may be made as part of the same upper component part, as different upper component parts that optionally are engaged together, and/or one or both of the exterior surface 102E and/or the interior surface 102I may be made from multiple component parts. FIG. 4C is a similar view to FIG. 4A, but the upper 102 and sole structure 104 are not illustrated in FIG. 4C, and FIG. 4C provides more of a perspective schematic view. FIGS. 4A and 4C show the fluid-filled bladder system 110 in the foot-insertion (or foot-removal) configuration (with the foot-support bladder system 120 containing a first volume of fluid V₁ and the foot-securing bladder system 130 containing a second volume of fluid V₂).

Comparisons of FIGS. 4A and 4B and/or FIGS. 4C and 4D illustrate transfer of the fluid-filled bladder system 110 between (a) the foot-insertion/foot-removal configuration (FIGS. 4A and 4C) and (b) the foot-securing configuration (FIGS. 4B and 4D). When a force F is applied to the foot-support bladder system 120 (e.g., by a wearer placing his/her foot in the shoe on the plantar support surface 120S of the foot-support bladder system 120), this force F causes fluid (e.g., air or other gas) in the foot-support bladder system 120 to move through the fluid-flow connecting system (e.g., conduits 140A and 140B shown in FIGS. 4A-4D) and into the foot-securing chambers 130A/130B as the surface 120S is pressed downward by the force F. This movement of fluid causes the fluid volume contained in foot-support bladder system 120 to decrease (e.g., to V₃) and the fluid volume contained in the foot-securing bladder system 130 to increase (e.g., to V₄). Thus, as evident from FIGS. 4A-4D, the first volume of fluid of the foot-support bladder system 120 (in the foot-insertion/removal configuration) is greater than the third volume of fluid of the foot-support bladder system 120 (in the foot-securing configuration), i.e., V₁>V₃, and the second volume of fluid of the foot-securing bladder system 130 (in the foot-insertion/removal configuration) is less than the fourth volume of fluid of the foot-securing bladder system 130 (in the foot-securing configuration), i.e., V₂<V₄. Also, changing from the foot-insertion configuration to the foot-securing configuration in such structures and configurations causes at least a first portion 132A of an outer surface 132 of the foot-securing bladder system 130 to extend further away from the exterior surface 102E of the upper 102 as compared to a position of the first portion 132A of the outer surface 132 of the foot-securing bladder system 130 in the foot-insertion configuration. In other words, changing from the foot-insertion configuration to the foot-securing configuration in this structure causes a first portion 132A of the outer surface 132 of the foot-securing chambers 130A, 130B to extend outward (further into the interior chamber of the article of footwear and/or toward one another) and to a location closer to (and to potentially engage and/or contact) a wearer's foot, to thereby help hold the wearer's foot in the shoe. The broken lines 134 in FIGS. 4B and 4D show the original location and shape of the outer surface 132 of the first portion 132A of the foot-securing chambers 130A, 130B in the foot-insertion configuration to help illustrate the changes provided by changing to the foot-securing configuration.

In at least some examples of this invention, if desired, the sole structure 104, the foot-support bladder system 120, and/or some other component may be provided to provide/ensure at least some minimal level of impact force attenuation for the foot support components and/or at least some minimal level of foot-support bladder system 120 fluid volume/inflation in the article of footwear 100. In other words, some type of “stop” system may be provided to prevent the foot-support bladder system 120 from “bottoming out” and/or otherwise providing insufficient impact force attenuation to the wearer's foot. As a specific example, FIGS. 4A and 4B illustrate a “stop member” 120A located within the foot-support bladder system 120 (and optionally engaged with at least one interior surface thereof). The stop member 120A may be a resilient member, such as a resilient foam component, another fluid-filled bladder/chamber (e.g., a fluid-filled bladder/chamber that is not connected to the foot-securing bladder system 130), one or more springs, or the like. As other examples, the stop member 120A may include top and bottom domes or “buttons” of resilient material provided on the inside or outside of foot-support bladder system 120 that engage or interface when a sufficient force F is applied. As yet other options or alternatives, one or more stop members may be provided independent from the foot-support bladder system 120 (e.g., not engaged therewith), e.g., engaged with the sole structure 104 (for example, as part of foam midsole component), and these stop members (e.g., the foam midsole structure) may act to limit the extent to which the sole structure 104 and/or foot-support bladder system 120 can compress under force F. Another alternative or additional “stop” system could include valving or switching (e.g., manual or electronically controlled and activated) that activates to limit fluid flow out of foot-support bladder system 120 (e.g., via conduits 140A/140B) after a predetermined volume has been moved out and/or after a predetermined volume moves into foot-securing bladder system 130. Other ways of limiting compression and/or deflation of the foot-support bladder system 120 also may be used without departing from this invention.

Once in the foot-securing configuration of FIGS. 4B and 4D, a fluid-flow control system 150 may be manipulated to close the fluid-flow connecting system (e.g., close conduits 140A-140D) to prevent further movement of fluid and to maintain the fluid-filled bladder system 110 in the foot-securing configuration. This can be accomplished, for example, by manually or electronically manipulating a switch or valve 150, e.g., while the user stands up in the shoe (applies force F), as will be explained in more detail below. In this manner, when changed to the foot-securing configuration, the foot-securing bladder system 130 (e.g., including one or more foot-securing chambers 130A-130D) increase in volume to move the outer surface(s) thereof closer to one another and to a location close to or in contact with the wearer's foot. This close proximity/contact help hold the wearer's foot in position when the shoe is worn.

FIGS. 5A through 5D schematically illustrate various steps involved in one example of securing an article of footwear to a wearer's foot in accordance with at least some examples of this invention. This method starts with providing an article of footwear that includes a foot-support bladder system 120 and a foot-securing bladder system 130, e.g., of the various types described above in conjunction with FIGS. 1A through 4D. For ease of reference and to avoid obscuring the relevant structures, FIGS. 5A-5D show only the fluid-filled bladder system 110 features. At the start of the procedure, the fluid-filled bladder system 110 is in the foot-insertion configuration, e.g., with the fluid-flow connecting system (e.g., conduits 140A-140D) in an open state to allow free flow of fluid between the foot-support bladder system 120 and the foot-securing bladder system 130.

FIG. 5B schematically illustrates the fluid-filled bladder system 110 as a foot (illustrated by broken lines 160) begins to be inserted into the interior chamber of the shoe and begins applying a force F to the foot-support bladder system 120 (e.g., by contacting plantar support surface 120S). As shown in FIG. 5B, in the foot-insertion configuration, first portion(s) 132A of the outer surface(s) 132 of the foot-securing bladder chambers 130A, 130B are retracted away somewhat from the wearer's foot 160 (and thus are positioned to allow relatively easy insertion of the foot 160).

As the foot 160 compresses the foot-support bladder system 120 (reducing it from volume V₁ to V₃) in response to the force F, fluid flows from the foot-support bladder system 120 into the foot-securing bladder system 130 (e.g., into chambers 130A and 130B, in this illustrated example) via fluid flow conduits 140A, 140B. FIG. 5C illustrates that the chambers 130A/130B have expanded in volume, closing the gap between the first portion 132A of the outer surface 132 of the chambers 130A,130B and the wearer's foot 160 (and moving the opposite first portions 132A of outer surfaces 132 of chambers 130A and 130B closer together). Also, as evident from these figures in conjunction with FIGS. 4A-4D, this movement of fluid causes the first portion 132A of the outer surface 132 of the foot-securing bladder system 130 (e.g., chambers 130A, 130B) to extend further away from the exterior surface 102E of the upper 102 as compared to a location of the first portion 132A of the outer surface 132 before the force F is applied. Also, as shown in FIGS. 5A and 5D, the surface 132B of the chambers 130A/130B opposite the first portion 132A of the outer surface 132 of the chamber bladders stay in the same (or substantially the same) locations in the transverse (side-to-side) direction (i.e., width W_(B) remains constant or substantially constant) in the foot-insertion configuration and the foot-securing configuration. The term “substantially constant” as used herein in this context means that the width W_(B) changes less than 10% between the foot-insertion configuration and the foot-securing configuration. Thus, the bladder chambers 130A, 130B predominantly deflect or move inward toward the interior volume of the shoe 100 (and interior width W_(II) in the foot-insertion configuration (FIG. 5A) is greater than the interior width W_(IS) in the foot-securing configuration (FIG. 5B), i.e., W_(II)>W_(IS)).

After the fluid is moved from the foot-support bladder system 120 to the foot-securing bladder system 130 through the fluid-flow connecting system (140A, 140B) in response to the force F, and optionally with the force F still being applied to the foot-support bladder system 120 (e.g., by the wearer's foot 160 standing down or otherwise applying force F on the support surface 120S), the fluid-flow connecting system 140A/140B may be closed by fluid-flow control system 150. This is shown in FIG. 5D by the large “X's” through the conduits 140A, 140B. This action prevents further movement of fluid from the foot-support bladder system 120 to the foot-securing bladder system 130 and prevents movement of fluid from the foot-securing bladder system 130 to the foot-support bladder system 120 while the foot 160 is contained within the fluid-filled bladder system 110 (and it maintains the fluid-filled bladder system 110 in the foot-securing configuration and close to and/or against the wearer's foot 160).

The step of closing the fluid-flow connecting system 140A/140B may be accomplished in any desired manner without departing from this invention, including, for example, by activating a manually controlled valve or switch, by activating an electronically controlled valve or switch, etc., including, for example, physically moving a closure element to physically “pinch shut” conduits 140A/140B, closing a valve, etc. Further example features of this aspect of the invention are described in more detail below in conjunction with FIGS. 7A and 7B.

FIGS. 6A through 6D schematically illustrate various steps involved in one example of loosening an article of footwear, e.g., to remove it from a wearer's foot, in accordance with at least some examples of this invention. This method starts with providing an article of footwear that includes a foot-support bladder system 120 and a foot-securing bladder system 130, e.g., of the various types described above in conjunction with FIGS. 1A through 4D. For ease of reference and to avoid obscuring the relevant structures, FIGS. 6A-6D show only the fluid-filled bladder system 110 features. At the start of this procedure, the fluid-filled bladder system 110 is in the foot-securing configuration, e.g., with the fluid-flow connecting system (e.g., conduits 140A-140D) in a closed state by fluid-flow control system 150 to prevent free flow of fluid between the foot-support bladder system 120 and the foot-securing bladder system 130 (e.g., the configuration shown in FIG. 5D, as shown by the large “X's” over the conduits 140A/140B in FIG. 6A).

For the loosening procedure, the force F is reduced on the support surface 120S of the foot-support bladder system 120, as shown in FIG. 6A by the reduced size of the force arrow F as compared to the size in FIG. 5D. “Reducing” the force may include completely removing the force, e.g., by the wearer lifting the foot off any contact surface and/or sitting down (e.g., in a chair or other support surface). Either before or after the force F is reduced, the fluid-flow controlling system 150 is controlled to move to an open state (e.g., to open conduits 140A/140B) and thereby allow fluid to flow between the foot-securing bladder system 130 and the foot-support bladder system 120. This is shown in FIG. 6B by the removal of the large “X's” as compared to FIG. 6A. As shown in FIG. 6B, the reduction in force coupled with opening of the fluid-flow control system 150 may cause fluid to move from the foot-securing bladder system 130 to the foot-support bladder system 120 through the fluid-flow connecting system (e.g., conduits 140A, 140B). These steps further may cause the first portion 132A of the outer surface 132 of the foot-securing bladder system 130 to “retract” or move at least somewhat, e.g., away from the wearer's foot 160 and/or toward the exterior surface 102E of the upper 102 (as compared to a location of the first portion 132A of the outer surface 132 before the force F was reduced and/or before the fluid-flow control system 150 was opened). This action also moves the opposite first portions 132A of outer surfaces 132 of chambers 130A and 130B away from one another. As further evident from FIG. 6B (as compared to 6A), this action also may cause the outer surfaces 132 of the bladder chambers 132A/132B to move outward (with respect to the wearer's foot 160) and toward the opposite surface 132B thereof (i.e., width W_(6B) is less than width W_(6A) in these illustrated examples). Notably, FIG. 6B also illustrates a larger gap between opposing surfaces 132A in chambers 130A and 130B (i.e., W_(IS) (FIG. 6A)<W_(II) (FIG. 6B)).

FIG. 6C illustrates the wearer's foot 160 lifting out from the fluid-filled bladder system 110, thereby leaving no external force on the plantar support surface 120S of the foot-support bladder system 120. This action may allow further fluid flow between the foot-securing bladder system 130 and the foot-support bladder system 120 and further retraction of the first portion 132A of the outer surface 132 of the chambers 130A/130B and return of the fluid-filled bladder system 110 to (or at least toward) the original foot-insertion configuration (e.g., back to the status of FIG. 5A). Note FIG. 6D.

As described above in conjunction with FIGS. 5A and 5D, the fluid-filled bladder system 110 may be configured, structured, and arranged in an article of footwear 100 such that the surfaces 132B of the chambers 130A/130B opposite the first portion 132A of the outer surface 132 of the chamber (i.e., the surface 132B opposite the surface 132 that extends or retracts from movement of the fluid) stay in the same (or substantially the same) relative locations in the transverse (side-to-side) direction. In some examples, this may mean that the width W_(B) shown in these figures remains constant or substantially constant in the foot-insertion/foot-removal configuration and the foot-securing configuration. The structure of the footwear 100 and/or the upper 102 can assist in helping maintain the surface(s) 132B in the desired (and substantially relatively constant) locations. For example, the exterior surface 102E of the upper 102 may be made more resistant to deformation than is at least the first portion 132A of the outer surface 132 of the foot-securing bladder system 130 such that the moving fluid step (from the foot insertion force F) causes the first portion 132A of the outer surface 132 of the foot-securing bladder system 130 to move more than it causes the exterior surface 102E of the upper 102 to move. This may be accomplished, for example, by making the exterior surface 102E of the upper 102 out of a relatively stiff material, by including one or more support ribs 102R (see FIGS. 4A and 4B) and/or other support structures around desired locations of the upper 102, or the like. Additionally or alternatively, if desired, if at least some portion of the foot-securing bladder system 130 (e.g., chamber 130A/130B) is located between the exterior surface 102E of the upper 102 and an interior surface 102I of the upper 102 (located opposite the exterior surface 102E), the exterior surface 102E of the upper 102 may be made more resistant to deformation than the interior surface 102I (e.g., by reinforcing the exterior surface 102E in any one or more of the manners described above). In such structures, the first portion 132A of the outer surface 132 of the foot-securing bladder system 130 may be positioned with respect to the exterior surface 102E and the interior surface 102I such that the moving fluid (during a foot-insertion/foot-securing configuration switch) causes the interior surface 102I to move or deflect more than it causes the exterior surface 102E to move or deflect.

FIG. 7A schematically illustrates an example fluid-flow control system 150 and its operation in accordance with at least some examples of this invention. As shown in FIG. 7A, the fluid-flow control system 150 of this example includes a switch 152, which may be mounted on the article of footwear 100, e.g., on the upper 102, on the tongue (if any), and/or, as shown in FIGS. 1A and 1B, on the sole structure 104. Activation of the switch 152 may change the status of fluid-flow in the fluid-filled bladder system 110 and allow conversion of the system 110 from the foot-insertion configuration to the foot-support configuration and/or from the foot-support configuration to the foot-insertion/foot-removal configuration. Activation of the switch 152, as shown by control arrows 154, may toggle the conduits 140A/140B between open and closed states. Activation of the switch 152 may physically cause the conduits 140A/140B to close off (e.g., pinch the conduit(s) 140A/140B closed by a corresponding pinching member), may insert a physical barrier in the conduit 140A/140B to close it off, may change a valve from an open configuration to a closed configuration, and/or may otherwise prevent fluid flow through the conduit 140A/140B (e.g., in manners known to those skilled in the art). The switch 152 may be activated, for example, at the time shown by FIG. 5D in the securing process and/or at the time shown by FIGS. 6A and/or 6B in the loosening process (e.g., before or after the force F on plantar support surface 120S is reduced or removed). Also, the switch 152 may be a manual switch (e.g., which physically moves another component to open/close conduits 140A/140B) or an electronic switch/valving without departing from this invention.

FIG. 7B schematically shows another example fluid-flow control system 150 in accordance with at least some examples of this invention. In this example, the fluid-flow control system 150 includes an input device 156 (e.g., a wireless transceiver), optionally mounted on the article of footwear 100, e.g., on the upper 102, on the tongue (if any), and/or, as shown in FIGS. 1A and 1B, on the sole structure 104. The input device 156 receives input (optionally a wireless signal 158), e.g., from a user operated device 170 (e.g., a cellular telephone, another electronic device, a keyboard, a footwear mounted input device, etc.), indicating a desire to change the fluid-filled bladder system 110 configuration from the foot-insertion/foot-removal configuration to the foot-support configuration and/or from the foot-support configuration to the foot-insertion/foot-removal configuration. The user operated device 170 may include a smart phone “app” or other user interface to allow input to generate the signal 158. Receipt of signal 158 at input device 156 will cause a microprocessor or other controller in the system to issue the signals needed to change the fluid-filled bladder system 110 and the fluid-flow control system 150 to the desired configuration(s) (e.g., including operation of one or more electronically controlled valves). Any desired types of remote control, communication protocols, and/or other electronic control systems/methods may be used without departing from the invention.

Optionally, if desired, as another potential feature of systems and methods in accordance with at least some examples of this invention, the fluid-flow control systems 150 of FIGS. 7A and/or 7B may allow/receive user input to further tighten and/or loosen the foot-securing bladder system 130 around the wearer's foot (e.g., to allow slight changes or “fine tuning” in the tightness up or down, potentially in a stepwise fashion, based on user input via device 170). This could be accomplished, for example, by moving fluid into and/or out of chambers 130A and/or 130B from one or more reserve fluid storage devices 172 and/or the ambient atmosphere via lines 174. Lines 174 alternatively could be used to supply more fluid from foot-support bladder system 120, if desired, e.g., under user control as described above. Additionally or alternatively, if desired, the “hardness” of the foot-support bladder system 120 also could be fine-tuned or controlled, e.g., by the fluid-control systems 150 of FIGS. 7A and/or 7B, to harden or soften the foot-support bladder system 120 under the wearer's foot (e.g., to allow slight changes or “fine tuning” in the hardness up or down, potentially in a stepwise fashion, based on user input via device 170). This could be accomplished, for example, by moving fluid into and/or out of the bladder system 120 from one or more reserve fluid storage device 176 and/or the ambient atmosphere via line 178. If present as a reserve fluid storage device, devices 172 and 176 (if both are present) actually may be formed as one storage device or multiple storage devices without departing from this invention.

The foot-securing bladder system 130 may be located at any desired one or more locations in the interior chamber of an article of footwear structure 100 without departing from this invention. Some examples are shown in FIGS. 8A-8E. More specifically, as shown in FIG. 8A, one or more foot-securing chambers (e.g., 130A/130B) of a foot-securing bladder system 130 may be located at a lateral heel area of the upper 102 and/or the medial heel area of the upper 102 (the opposite side from the view shown in FIG. 8A may be a mirror image of the view of FIG. 8A or other similar arrangement of chamber(s) 130A/130B). In this configuration, the chambers 130A/130B may “squeeze” against (and optionally contact) the side ankle/heel areas of the wearer's foot when the fluid-filled bladder system 110 is in the foot-securing configuration.

Additionally or alternatively, as shown in FIG. 8B, one or more foot-securing chambers (e.g., 130A/130B) of a foot-securing bladder system 130 may be located at a lateral midfoot area of the upper 102 and/or the medial midfoot area of the upper 102 (the opposite side from the view shown in FIG. 8B may be a mirror image of the view of FIG. 8B or other similar arrangement of chamber(s) 130A/130B). In this configuration, the chambers 130A/130B may “squeeze” against (and optionally contact) the side midfoot areas of the wearer's foot and/or may extend at least somewhat over the top or instep area of a wearer's foot (e.g., toward vamp or tongue region 180 of the article of footwear 100) when the fluid-filled bladder system 110 is in the foot-securing configuration.

As another additional or alternative example, as shown in FIG. 8C, one or more foot-securing chambers (e.g., 130A/130B) of a foot-securing bladder system 130 may be located at a lateral forefoot area of the upper 102 and/or the medial forefoot area of the upper 102 (the opposite side from the view shown in FIG. 8C may be a mirror image of the view of FIG. 8C or other similar arrangement of chamber(s) 130A/130B). In this configuration, the chambers 130A/130B may “squeeze” against (and optionally contact) the side forefoot areas of the wearer's foot and/or may extend at least somewhat over the top or instep area of a wearer's foot (e.g., toward vamp, tongue, or forefoot region 180 of the article of footwear 100) when the fluid-filled bladder system 110 is in the foot-securing configuration.

FIG. 8D illustrates other example additional or alternative placement options for one or more foot-securing chambers (e.g., 130A/130B) of a foot-securing bladder system 130. In this example, a single chamber 130A is located to extend across an instep and/or forefoot (forward toe) covering area of the upper 102 (the opposite side from the view shown in FIG. 8D may be a mirror image of the view of FIG. 8D or other similar arrangement of chamber(s) 130A), and the chamber 130A may extend continuously from one side to the other. In this configuration, the chamber 130A may “squeeze” against (and optionally contact) the side forefoot areas of the wearer's foot and/or may extend over the top or instep area of a wearer's foot when the fluid-filled bladder system 110 is in the foot-securing configuration.

Additionally or alternatively, as shown in the example of FIG. 8E, one or more foot-securing chambers (e.g., 130A) of a foot-securing bladder system 130 may be located to extend around a rear heel area 182 of the upper 102 (the opposite side from the view shown in FIG. 8E may be a mirror image of the view of FIG. 8E or other similar arrangement of chamber(s) 130A), and the chamber 130A may extend continuously from one side to the other around the rear heel area 182. In this configuration, the chamber 130A may “squeeze” against (and optionally contact) the side and rear heel areas of the wearer's foot when the fluid-filled bladder system 110 is in the foot-securing configuration.

Any combination or sub-combination of chambers and/or chamber configurations, e.g., of the types and/or at the locations shown in FIGS. 8A-8E, may be used in an individual article of footwear 100 without departing from this invention. Any number, arrangement, sizes, and/or locations of foot-securing chambers (e.g., 130A-130D) may be used, e.g., to provide a desired level of foot secureness for the anticipated activity.

As described above, several components of articles of footwear 100 in accordance with various examples and aspects of this invention include fluid-tight and fluid-filled bladders (e.g., foot-support bladder system 120, foot-securing bladder system 130, and the foot-securing chambers 130A-130D). Such fluid-filled bladders are generally known and used in the footwear arts for impact force attenuation, and therefore, a more detailed discussion of these bladders and potential methods of making them are omitted. FIGS. 9A and 9B, however, illustrate some potential features of such bladder systems, e.g., that may help and/or allow them to deform/extend/retract and/or change volume in a desired manner, e.g., in systems and methods according to some examples of this invention.

For example, as shown in these figures, a bladder 200 (e.g., for use in foot-support bladder system 120, foot-securing bladder system 130, and/or the foot-securing chambers 130A-130D) may be made from two sheets 202A/202B (e.g., of thermoplastic elastomer material) bonded together at a seam 204 (e.g., welded together). A tensile member 210 is provided inside the volume 206 defined by the bladder exterior envelope sheets 202A/202B. The tensile member 210 may include bases 210B attached to the interior surfaces of sheets 202A/202B (e.g., by welding, adhesives, etc.), and the bases 210B may be interconnected by a plurality of bands, fibers, and/or strands 212 (hereinafter generically called “strands”). The strands 212 may be formed at lengths such that: (a) under a lower fluid volume condition in the interior volume 206 of the bladder 200 (e.g., under the foot-insertion/foot-removal configuration for bladder chambers 130A-130D), the strands 212 are not taut (and potentially the sidewalls of the bladder 200 are not taut and/or are stretchable), whereas (b) under a higher fluid volume condition in the interior volume 206 of the bladder 200 (e.g., under the foot-supporting configuration for bladder chambers 130A-130D), the strands 212 are taut (or more taut) (and potentially the sidewalls of the bladder are taut, more taut, and/or stretched). The change to the higher fluid volume condition can expand the shape of the bladder 200, e.g., when bladder chambers 130A-130D move to the foot-securing configuration/position. Compare heights H1 and H2 in FIGS. 9A and 9B. In this manner, the bladder 200 can expand to engage or come in close proximity to a wearer's foot in the foot-securing configuration (FIG. 9B) and retract or loosen (or somewhat collapse) when the fluid-flow control system 150 changes the fluid-filled bladder system 110 from the foot-securing configuration to the foot-insertion (or foot-removal) configuration (FIG. 9A).

As another potential option or alternative, if desired, rather than being untaut or taut, the strands 212 may be made from a stretchable or elastic material such that the strand 212 material stretches in one configuration (e.g., in the foot-securing configuration of foot-securing bladder chambers 130A-130D in FIG. 9B) and retracts in the other configuration (e.g., in the foot-insertion/foot-removal configuration of foot-securing bladder chambers 130A-130D in FIG. 9A). The sidewalls of the bladder 200 may convert between taut/stretched in one configuration and untaut/unstretched (or less stretched) in the other configuration. If desired, at least a portion of the sidewalls of bladder 200 may include an elastic/stretchable component material to facilitate the desired movement/deflection of the bladder 200 sidewalls.

FIG. 10 illustrates another example bladder structure 250 that may be used to control/convert the shape of a bladder 250 in the foot-securing configuration versus the foot-insertion/removal configuration. This example bladder structure 250 is similar to that shown in FIGS. 9A and 9B, including two sheets 202A/202B (e.g., of thermoplastic elastomer material) bonded together at a seam 204 (e.g., welded together); a tensile member 210 provided inside the volume 206 including at least one base 210B attached to the interior surfaces of sheets 202A/202B; and bases 210B interconnected by a plurality of fibers or strands 212. The sidewall of bladder 250 may include stretchable or elastic materials/properties as described above for bladder 200. In this structure 250, however, a portion of one base 210B includes an “adhesion inhibitor” 252 that prevents the base 210B from bonding (e.g., by adhesive, RF welding, etc.) to the interior surface of sheet 202A. In this manner, increased fluid volume within the volume 206 can cause a portion 132A of the outer surface of this bladder 250 to bulge, deflect, or expand outward (e.g., under the foot-supporting configuration for bladder chambers 130A-130D) and decreased fluid volume within volume 206 can cause portion 132A of the outer surface 132 of bladder to be softer, collapse, and/or potentially retract or loosen from the foot (e.g., under the foot-insertion/foot-removal configuration for bladder chambers 130A-130D).

Adhesion/bond inhibiting materials 252 (and/or adhesion promoting materials) and their use to selectively shape fluid-filled bladders are known in the art, e.g., as shown, for example, in U.S. Patent Appln. Publn. No. 2015/0013190 A1, which publication is entirely incorporated herein by reference. Use of interior bonds between bladder layers and/or other ways of controlling the shapes of fluid-filled bladders may be used without departing from this invention.

One potential advantageous feature of articles of footwear in accordance with at least some examples of this invention is that the foot can be secured in the article of footwear in a “laceless,” “strapless,” and/or “buckleless” manner, e.g., optionally with the fluid-filled bladder system 110 being the only system holding the shoe onto the wearer's foot.

Additionally or alternatively, if desired, articles of footwear in accordance with at least some aspects of this invention, including articles of athletic footwear, may be structured so that the wearer's foot may be inserted into the article of footwear in a “hands-free” manner (e.g., akin to a “slipper,” “clog,” or “slip on” type shoe). The rib structures 102R and/or other upper 102 exterior surface 102E reinforcements described above in conjunction with FIGS. 4A and 4B may assist in providing these types of “hands-free” insertion configurations (e.g., the reinforcing rib structures 102R and/or other features of the exterior surface 102E of the upper 202 described above may help prevent the heel area of the upper 102, particularly around the foot-insertion opening 102O, from collapsing under contact forces as the wearer inserts his/her foot. For articles of footwear that include fluid-filled bladder systems, e.g., 110, of the types described above, placement of the footwear 100 in the foot-insertion configuration also can help provide “hands-free” foot insertion capabilities as the foot-receiving opening 102O may be opened somewhat wider (as any heel based foot-securing bladder chambers 130A/130B are retracted away from the interior chamber).

Some example structures in accordance with aspects of this invention may include one or more different (e.g., additional and/or alternative) features to assist in providing a “hands-free” foot insertion configuration. FIG. 11 illustrates an example article of footwear 300 that includes a sole structure 104 (e.g., made from one or more parts) and an upper 102 (made from one or more parts) engaged with this sole structure 104. The upper 102: (a) includes an exterior structure (e.g., exterior surface 102E) extending in a direction away from the sole structure 104 and (b) at least in part, defines a foot-receiving opening 102O that provides access to the foot receiving interior chamber of the footwear 300. In this illustrated example, at least a portion of an upper rim 302 or an upper interior edge 302E of the foot-receiving opening 102O includes a friction reducing agent 304. The friction reducing agent 304 (shown in broken lines in FIG. 11 because it is inside the upper 102) may include a polytetrafluoroethylene component or other friction reducing material. The friction reducing agent 304 will better allow a wearer's foot (e.g., optionally contained in a sock) to slide with respect to the upper 102 interior surface 102I should the wearer's foot come into contact with the portion of the upper 102 including the friction reducing agent 304. In this manner, the easier sliding of the foot along the friction reducing agent 304 will be less likely to apply downward force to the exterior structure of the upper 102 sufficient to cause the upper 102 to collapse at the foot insertion area as the foot is being inserted (as compared to similar relative sliding of the foot with respect to the upper and/or force that would be generated if the upper 102 did not include the friction reducing agent 304).

The friction reducing agent 304 may be applied to any desired portion and/or proportion of the upper rim 302 and/or the upper interior edge 302E of the foot-receiving opening 102O of the upper 102, in any desired number of discrete or separated sections or patches. Additionally, the friction reducing agent 304 may be applied along any desired vertical height downward from the upper rim 302 or the upper interior surface 302E without departing from this invention. In some examples of this invention, the friction reducing agent 304 may be applied in one or more strips or patches extending downward from the upper rim 302 for a distance of up to 30 mm, and in some examples, for a distance up to 25 mm, or a distance up to 20 mm. As other options, if desired, the friction reducing agent 304 may be applied to the interior surface of the upper in one or more sections, strips, or patches in any desired portion or proportion from at or proximate to the upper rim 302 down to the sole structure or sockliner (e.g., including from 5% to 100% of this height dimension, and in some examples, from 5% to 50% of this height dimension, or even from 7.5% to 35% of this height dimension). As used herein in this context, friction reducing agent 304 is located “proximate to” another component (such as the upper rim 302 and/or foot-receiving opening 102O) if at least some portion of the friction reducing agent is located at and/or within 10 mm of the other component (such as the upper rim 302 and/or foot-receiving opening 102O). The term “proximate to” as used in this context also includes friction reducing agent 304 directly in contact with or extending to or over the other component (e.g., friction reducing agent 304 that originates at or extends around the upper rim 302 from the exterior surface 102E of the upper 102 to the interior surface 102I of the upper 102 is considered “proximate to” the upper rim 302, as used in this specification).

Friction reducing agent 304 also may be applied to outer surfaces 132 of bladder chambers 130A-130D, if desired, e.g., when such bladder chamber(s) 130A-130D are present/exposed in the foot-insertion area. The friction reducing agent 304 may be applied in the form of a tape that adheres to a component (upper interior surface edge 302E, bladder surface 132, etc.), wherein the exposed surface of the tape that may contact the wearer includes the friction reducing agent 304.

As mentioned above, the exterior structure of the upper 102 at least around some portion of the foot-receiving opening 102O may be formed to be resistant to buckling under a foot insertion force applied to the foot-receiving opening 102O. One example of such buckling resistant structures is shown by ribs 102R in FIG. 11. Other or additional features, such as choice of materials, exoskeleton structures, or the like, could be used to create/enhance buckling resistance around the foot-receiving opening 102O.

FIGS. 1A-1C show additional potential examples and features of these aspects of the invention. More specifically, as shown in the example of these figures, three separate sections of friction reducing agent 304 (e.g., as a tape or adhesive strip or section) are engaged with the upper 102, specifically, a lateral side section 304L of friction reducing agent, a medial side section 304M of friction reducing agent, and a heel section 304H of friction reducing agent are provided at (or “proximate” to) the foot-receiving opening 102O. In fact, in these illustrated examples, the sections 304L, 304M, and 304H of friction reducing agent extend over the foot-receiving opening 102O upper rim and along both the interior upper edge and the exterior upper edge of the upper 102 proximate to the foot-receiving opening 102O upper rim. More or fewer sections of friction reducing agent may be used without departing from this invention, and the friction reducing agent may be provided around any desired portion or proportion of the outer rim perimeter. The various sections 304L, 304M, and 304H of friction reducing agent may be made of the same or two or more different materials without departing from this invention. Additionally or alternatively, if desired, a single section of friction reducing agent 304 may be made from one or more distinct friction reducing materials.

II. Conclusion

The present invention is disclosed above and in the accompanying drawings with reference to a variety of embodiments and/or options. The purpose served by the disclosure, however, is to provide examples of various features and concepts related to the invention, not to limit the scope of the invention. One skilled in the relevant art will recognize that numerous variations and modifications may be made to the features of the invention described above without departing from the scope of the present invention, as defined by the appended claims. 

What is claimed is:
 1. An article of footwear, comprising: an upper including an exterior surface; a sole structure engaged with the upper, wherein at least one of the sole structure and the upper define an interior volume configured to receive a wearer's foot; and a fluid-filled bladder system including: a foot-support bladder system providing at least a portion of a plantar support surface, wherein the foot-support bladder system is engaged with or formed as part of at least one of the upper or the sole structure, a foot-securing bladder system engaged with the upper and located at least partially within the exterior surface of the upper, a fluid-flow connecting system placing the foot-support bladder system and the foot-securing bladder system in fluid communication with one another, and a fluid-flow control system configured to control flow of fluid between the foot-support bladder system and the foot-securing bladder system through the fluid-flow connecting system, wherein the fluid-flow control system is configured to change the fluid-filled bladder system between: (a) a foot-insertion configuration in which the foot-support bladder system contains a first volume of fluid and the foot-securing bladder system contains a second volume of fluid, and (b) a foot-securing configuration in which the foot-support bladder system contains a third volume of fluid and the foot-securing bladder system contains a fourth volume of fluid, wherein the first volume of fluid is greater than the third volume of fluid and the second volume of fluid is less than the fourth volume of fluid, and wherein a first portion of an outer surface of the foot-securing bladder system extends further away from the exterior surface of the upper in the foot-securing configuration as compared to a position of the first portion of the outer surface of the foot-securing bladder system in the foot-insertion configuration.
 2. The article of footwear according to claim 1, wherein the foot-securing bladder system includes a first foot-securing chamber located at one or more of: a lateral heel area of the upper, a medial heel area of the upper, a rear heel area of the upper, a lateral midfoot area of the upper, a medial midfoot area of the upper, a lateral forefoot area of the upper, a medial forefoot area of the upper, an instep area of the upper, or a forward toe covering portion of the upper.
 3. The article of footwear according to claim 1, wherein the foot-securing bladder system includes a first foot-securing chamber that includes the first portion of the outer surface of the foot-securing bladder system and a second foot-securing chamber containing a second portion of the outer surface of the foot-securing bladder system, wherein the second portion of the outer surface of the foot-securing bladder system extends further away from the exterior surface of the upper in the foot-securing configuration as compared to a position of the second portion of the outer surface of the foot-securing bladder system in the foot-insertion configuration.
 4. The article of footwear according to claim 3, wherein the first foot-securing chamber is located on a lateral side of the upper and the second foot-securing chamber is located on a medial side of the upper.
 5. The article of footwear according to claim 4, wherein the fluid-flow connecting system includes a first fluid conduit connecting the foot-support bladder system and the first foot-securing chamber and a second fluid conduit connecting the foot-support bladder system and the second foot-securing chamber.
 6. The article of footwear according to claim 3, wherein the first foot-securing chamber is located on a lateral side of the upper and the second foot-securing chamber is located on the lateral side of the upper.
 7. The article of footwear according to claim 6, wherein the fluid-flow connecting system includes a first fluid conduit connecting the foot-support bladder system and the first foot-securing chamber and a second fluid conduit connecting the foot-support bladder system and the second foot-securing chamber.
 8. The article of footwear according to claim 6, wherein the fluid-flow connecting system includes a first fluid conduit connecting the foot-support bladder system and the first foot-securing chamber, and wherein the fluid-filled bladder system further includes a second fluid conduit connecting the first foot-securing chamber and the second foot-securing chamber.
 9. The article of footwear according to claim 3, wherein the first foot-securing chamber is located on a medial side of the upper and the second foot-securing chamber is located on the medial side of the upper.
 10. The article of footwear according to claim 9, wherein the fluid-flow connecting system includes a first fluid conduit connecting the foot-support bladder system and the first foot-securing chamber and a second fluid conduit connecting the foot-support bladder system and the second foot-securing chamber.
 11. The article of footwear according to claim 9, wherein the fluid-flow connecting system includes a first fluid conduit connecting the foot-support bladder system and the first foot-securing chamber, and wherein the fluid-filled bladder system further includes a second fluid conduit connecting the first foot-securing chamber and the second foot-securing chamber.
 12. The article of footwear according to claim 1, wherein the foot-securing bladder system includes a first foot-securing chamber located at a medial heel area of the upper and a second foot-securing chamber located at a lateral heel area of the upper.
 13. The article of footwear according to claim 1, wherein the foot-securing bladder system includes a first foot-securing chamber that extends around a rear heel area of the upper from a medial heel area of the upper to a lateral heel area of the upper.
 14. The article of footwear according to claim 1, wherein the foot-securing bladder system includes a first foot-securing chamber located at a medial midfoot area of the upper and a second foot-securing chamber located at a lateral midfoot area of the upper.
 15. The article of footwear according to claim 1, wherein the foot-securing bladder system includes a first foot-securing chamber located at a medial forefoot area of the upper and a second foot-securing chamber located at a lateral forefoot area of the upper.
 16. The article of footwear according to claim 1, wherein the first portion of the outer surface of the foot-securing bladder system is located at one or more of: a lateral heel area of the upper, a medial heel area of the upper, a rear heel area of the upper, a lateral midfoot area of the upper, a medial midfoot area of the upper, a lateral forefoot area of the upper, a medial forefoot area of the upper, an instep area of the upper, or a forward toe covering portion of the upper.
 17. The article of footwear according to claim 1, wherein changing the fluid-filled bladder system from the foot-insertion configuration to the foot-securing configuration involves movement of fluid only between the foot-support bladder system and the foot-securing bladder system, and wherein changing the fluid-filled bladder system from the foot-securing configuration to the foot-insertion configuration involves movement of fluid only between the foot-support bladder system and the foot-securing bladder system.
 18. The article of footwear according to claim 1, wherein the fluid-flow control system includes one or more of: a non-electronic switch for opening and closing at least a portion of the fluid-flow connecting system; an electronic controller for opening and closing at least a portion of the fluid-flow connecting system; an input device for receiving an electronic signal for opening and closing at least a portion of the fluid-flow connecting system; and a wireless transceiver.
 19. An article of footwear, comprising: a sole structure; and an upper engaged with the sole structure, wherein the upper (a) includes an exterior structure extending in a direction away from the sole structure and (b) at least in part, defines a foot-receiving opening, wherein at least a portion of an upper rim or an upper interior edge of the foot-receiving opening of the upper includes a friction reducing agent.
 20. The article of footwear according to claim 19, wherein the friction reducing agent includes a polytetrafluoroethylene component. 